Driving Stability of an Agricultural Articulated Vehicle based on the Closed-loop System

Abstract

In stability analysis of systems, it’s common to consider the open-loop control based on two-dimensional motion equations. However, actual driving involves steering control through the closed-loop system, and accidents occur in the process. Therefore, stability analysis was conducted based on the closed-loop control system. The results of simulation confirmed that although the open-loop system can become unstable, it can be stabilized by the closed-loop control system. However, as the driver’s preview distance reduces, the damping capability of the vehicle following a target course deteriorates and becomes unstable. Theoretically, it was clarified that even small-sized tractors used in Japan can exhibit unstable behavior such as jackknifing at high speeds, which can lead to accidents if the driver’s preview distance becomes small.